Add a field.virtual? method

lib/scoped_search/definition.rb

@@ -107,6 +107,11 @@ def key_klass
         end
       end
 
+      # Returns true if this is a virtual field.
+      def virtual?
+        !ext_method.nil?
+      end
+
       # Returns the ActiveRecord column definition that corresponds to this field.
       def column
         @column ||= begin

lib/scoped_search/query_builder.rb

@@ -113,7 +113,7 @@ def order_by(order, &block)
     # By default, it will simply look up the correct SQL operator in the SQL_OPERATORS
     # hash, but this can be overridden by a database adapter.
     def sql_operator(operator, field)
-      raise ScopedSearch::QueryNotSupported, "the operator '#{operator}' is not supported for field type '#{field.type}'" if !field.ext_method and [:like, :unlike].include?(operator) and !field.textual?
+      raise ScopedSearch::QueryNotSupported, "the operator '#{operator}' is not supported for field type '#{field.type}'" if !field.virtual? and [:like, :unlike].include?(operator) and !field.textual?
       SQL_OPERATORS[operator]
     end
 
@@ -210,7 +210,7 @@ def set_test(field, operator,value, &block)
     # <tt>operator</tt>:: The operator used for comparison.
     # <tt>value</tt>:: The value to compare the field with.
     def sql_test(field, operator, value, lhs, &block) # :yields: finder_option_type, value
-      return field.to_ext_method_sql(lhs, sql_operator(operator, field), value, &block) if field.ext_method
+      return field.to_ext_method_sql(lhs, sql_operator(operator, field), value, &block) if field.virtual?
 
       yield(:keyparameter, lhs.sub(/^.*\./,'')) if field.key_field
 
@@ -554,7 +554,7 @@ def sql_test(field, operator, value, lhs, &block)
       # Switches out the default LIKE operator in the default <tt>sql_operator</tt>
       # method for ILIKE or @@ if full text searching is enabled.
       def sql_operator(operator, field)
-        raise ScopedSearch::QueryNotSupported, "the operator '#{operator}' is not supported for field type '#{field.type}'" if !field.ext_method and [:like, :unlike].include?(operator) and !field.textual?
+        raise ScopedSearch::QueryNotSupported, "the operator '#{operator}' is not supported for field type '#{field.type}'" if !field.virtual? and [:like, :unlike].include?(operator) and !field.textual?
         return '@@' if [:like, :unlike].include?(operator) && field.full_text_search
         case operator
           when :like   then 'ILIKE'

spec/unit/query_builder_spec.rb

@@ -38,6 +38,7 @@
 
   it "should validate value if validator selected" do
     field = double('field')
+    field.stub(:virtual?).and_return(false)
     field.stub(:only_explicit).and_return(true)
     field.stub(:field).and_return(:test_field)
     field.stub(:validator).and_return(->(_value) { false })
@@ -49,6 +50,7 @@
 
   it "should validate value if validator selected" do
     field = double('field')
+    field.stub(:virtual?).and_return(false)
     field.stub(:only_explicit).and_return(true)
     field.stub(:field).and_return(:test_field)
     field.stub(:ext_method).and_return(nil)
@@ -65,6 +67,7 @@
 
   it "should display custom error from validator" do
     field = double('field')
+    field.stub(:virtual?).and_return(false)
     field.stub(:only_explicit).and_return(true)
     field.stub(:field).and_return(:test_field)
     field.stub(:validator).and_return(->(_value) { raise ScopedSearch::QueryNotSupported, 'my custom message' })